Gas Turbine Engine Systems Involving Variable Nozzles with Flexible Panels

ABSTRACT

Gas turbine engine systems involving flexible panels are provided. In this regard, a representative flexible panel assembly for a gas turbine engine includes: a flexible panel operative to define at least one of a throat area and an exit area of a nozzle of a gas turbine engine, the panel being further operative to selectively exhibit a range of positions to regulate exhaust of the engine.

BACKGROUND

1. Technical Field

The disclosure generally relates to gas turbine engines.

2. Description of the Related Art

Varying the nozzle exhaust area of a gas turbine engine can affect engine performance. By way of example, varying the nozzle exhaust area can alter propulsive efficiency, fan stability, noise output, and/or fuel consumption.

SUMMARY

Gas turbine engine systems involving variable nozzles with flexible panels are provided. In this regard, an exemplary embodiment of a flexible panel assembly for a gas turbine engine comprises: a flexible panel operative to define at least one of a throat area and an exit area of a nozzle of a gas turbine engine, the panel being further operative to selectively exhibit a range of positions to regulate exhaust of the engine.

An exemplary embodiment of a nozzle assembly for a gas turbine engine comprises: a nozzle having a throat area and an exit area; and a flexible panel operative to variably alter at least one of the throat area and the exit area to regulate exhaust flow of the nozzle.

An exemplary embodiment of a gas turbine engine comprises: a compressor; a turbine operative to drive the compressor; and a nozzle assembly positioned downstream of the turbine, the nozzle assembly defining a throat area and an exit area and having a flexible panel operative to selectively move between an open position and a closed position such that gas flowing through the nozzle is regulated.

Other systems, methods, features and/or advantages of this disclosure will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description and be within the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is a schematic diagram depicting an exemplary embodiment of a gas turbine engine.

FIG. 2 is a cross-sectional perspective diagram of the gas turbine engine of FIG. 1.

FIG. 3 is a perspective diagram depicting an exemplary embodiment of a nozzle assembly.

FIG. 4 is a schematic diagram depicting the flexible panel of the embodiment of FIG. 3 in a planar view.

DETAILED DESCRIPTION

Gas turbine engine systems involving variable nozzles with flexible panels are provided, several exemplary embodiments of which will be described in detail. In some embodiments, such a flexible panel is deflected in a gas turbine engine to create a desired shape in order to vary the nozzle exhaust area of the engine dynamically. Varying the nozzle exhaust area in a gas turbine engine can alter engine performance characteristics such as increasing fuel efficiency.

As shown in FIGS. 1 and 2, gas turbine engine 100 includes a compressor section 102, a combustion section 104, a turbine section 106, and an exhaust section 108. Engine 100 also includes a nozzle assembly 10, located at the aft end of the exhaust section 108, that defines a nozzle throat area 12 and a nozzle exit area 14, which is located downstream of the throat area. A duct 16 interconnects the gas path from the compressor section to the nozzle assembly 10. As such, duct 16 routes a gas stream 26 to the nozzle assembly, which then discharges the gas stream through the throat area and exit area. Notably, performance of engine 100 can be affected by regulating gas stream 26 by varying the nozzle assembly 10 at nozzle throat area 12 and/or nozzle exit area 14.

In this regard, reference is made to the perspective diagram of FIG. 3, which depicts an exemplary embodiment of a nozzle assembly 10 that incorporates a flexible panel 34. As shown in FIG. 3, flexible panel 34 is positioned at nozzle throat area 12 and nozzle exit area 14 to influence gas stream 26 exiting through the nozzle assembly 10. In some embodiments, the nozzle assembly 10 can be a third stream exhaust nozzle regulating a third stream ducted from the compressor section of a gas turbine engine.

The flexible panel 34 is configured to be variably deflected along a range of positions between a full open position, at which the nozzle assembly 10 exhibits a maximum exit area, and a full closed position, at which the nozzle assembly 10 exhibits a minimum exit area. As the flexible panel 34 is variably positioned, gas stream 26 (entering from a duct 16 of the nozzle assembly 10) is regulated.

The nozzle assembly 10 also incorporates a support structure 32 located within a lower cavity 36. The support structure 32 is configured to provide alignment and structural support to the flexible panel 34 from the underside (i.e., the non-gas path side) as the flexible panel 34 is variably positioned. In some embodiments (such as in FIG. 3), the support structure 32 is a truss structure including multiple triangular units constructed with beam members whose ends are connected at joints.

The flexible panel 34 incorporates stiffening stays 30 to maintain the throat profile of the nozzle assembly 10. The stiffening stays 30 are structural stiffeners tailored to provide a desired aerodynamic shaping of the flexible panel 34 at key performance locations over the entire range of motion of the flexible panel 34. In this embodiment, the stiffening stays 30 are formed of elongated strips of semi-rigid material extending across the width of the panel, although various other shapes, orientations and/or materials can be used in other embodiments.

In some embodiments, the flexible panel 34 may be all or partially comprised of a flexible elastomeric material, such as a fluorosilicone elastomer composite. Such a panel can be particularly well adept at sealing undesirable cracks and gaps. Metallics, organic composites, and ceramic composite materials are also envisioned to be suitable panel materials depending on placement within the panel structure and engine application. In higher temperature applications, for example, edge sealing could be performed with flexible metallic elements to cover cracks and gaps. Additionally, the relatively low translation and deflection requirements of the flexible panel 34 to vary the nozzle throat area 12 and/or nozzle exit area 14 can result in reduced actuation load requirements for positioning the panel.

In some embodiments, a nozzle assembly can incorporate a pressurized plenum. The pressurize plenum can be located in a lower cavity 36, for example, on a side of the panel opposite the gas path. Such a pressurized plenum is configured to provide pressure balancing of the panel to reduce actuation loads.

FIG. 4 is a schematic diagram depicting the nozzle assembly 10 of FIG. 3. As shown in FIG. 4, the gas stream 26 passes through duct 16 and nozzle throat area 12 and exits nozzle assembly 10 at nozzle exit area 14. As the gas stream 26 passes over the flexible panel 34, the gas stream is regulated by the nozzle throat area 12 and the nozzle exit area 14, the shape of each of which can be affected by positioning of the flexible panel 34.

Notably, the embodiment of FIG. 4 incorporates stiffening ribs (e.g., rib 44) on the underside of the flexible panel 34. The stiffening ribs are configured to deflect the flexible panel 34 to a desired shape in order to regulate the gas stream 26 and affect engine performance. As the flexible panel 34 is deflected by the stiffening ribs, the nozzle throat area 12 and nozzle exit area 14 are varied to operatively regulate the gas stream 26. The stiffening ribs are configured to be actuated via an actuator 42 that is coupled to the ribs at actuation point 40. In this embodiment, actuator 42 moves the stiffening ribs 44 about actuation point 40 to vary the shape of the flexible panel 34. By way of example, the actuator 42 is mechanically coupled to the flexible panel 34. In this regard, actuator 42 can be a hydraulic motor, for example. The actuator 42 can be located in the lower cavity 36 of the nozzle assembly 10.

The actuation mechanism between the actuator 42 and flexible panel 34 can be optimized for expected operating conditions and can incorporate one or more of a variety of linkages, levers, gears, and/or cam designs, chosen to facilitate reduced actuator loading yet increase operating speed.

It should be emphasized that the above-described embodiments are merely possible examples of implementations set forth for a clear understanding of the principles of this disclosure. Many variations and modifications may be made to the above-described embodiments without departing substantially from the spirit and principles of the disclosure. By way of example, in some embodiments, a flexible panel 34 can be configured to alter a nozzle throat asymmetrically in order to affect yaw vectoring of the flow. In some embodiments, this can be accomplished by the use of differential actuation of multiple actuators. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the accompanying claims. 

1. A flexible panel assembly for a gas turbine engine, the flexible panel assembly comprising: a flexible panel operative to define at least one of a throat area and an exit area of a nozzle of a gas turbine engine, the panel being further operative to selectively exhibit a range of positions to regulate exhaust of the engine.
 2. The flexible panel assembly of claim 1, further comprising: a stiffening rib configured to deflect the flexible panel.
 3. The flexible panel assembly of claim 2, further comprising: an actuator connected to the stiffening rib and operative to position the stiffening rib such that the flexible panel is deflected.
 4. The flexible panel assembly of claim 1, wherein the flexible panel is configured to be placed in at least one of a throat area and an exit area of a third stream exhaust nozzle to variably open and close the nozzle exit area and operatively regulate a third stream exhaust.
 5. The flexible panel assembly of claim 1, wherein the flexible panel is formed at least partially of an elastomeric material.
 6. The flexible panel assembly of claim 1, wherein the flexible panel is formed at least partially of an organic matrix composite.
 7. The flexible panel assembly of claim 1, wherein the flexible panel further comprises a stiffening stay operative to maintain a profile of the throat area.
 8. The flexible panel assembly of claim 1, wherein the flexible panel further comprises a support structure operative to support the flexible panel.
 9. The flexible panel assembly of claim 1, wherein the support structure is located on a non-gas path side of the flexible panel.
 10. A nozzle assembly for a gas turbine engine, the nozzle assembly comprising: a nozzle having a throat area and an exit area; and a flexible panel operative to variably alter at least one of the throat area and the exit area to regulate exhaust flow of the nozzle.
 11. The nozzle assembly of claim 10, further comprising: a stiffening rib operative to deflect the flexible panel such that at least one of the throat area and the exit area is altered.
 12. The nozzle assembly of claim 11, further comprising: an actuator, connected to the stiffening rib, operative to deflect the flexible panel by positioning the stiffening rib.
 13. The nozzle assembly of claim 10, wherein the panel is operative to symmetrically affect the exhaust flow with respect to yaw.
 14. The nozzle assembly of claim 10, wherein the nozzle assembly further comprises a support structure operative to support the flexible panel.
 15. The nozzle assembly of claim 10, further comprising a cavity located on a non-gas path side of the panel, the cavity being operative to reduce an actuation load associated with positioning of the panel by reducing pressure imbalances on the non-gas path and gas path sides of the panel.
 16. A gas turbine engine comprising: a compressor; a turbine operative to drive the compressor; and a nozzle assembly positioned downstream of the turbine, the nozzle assembly defining a throat area and an exit area and having a flexible panel operative to selectively move between an open position and a closed position such that gas flowing through the nozzle is regulated.
 17. The gas turbine engine of claim 16, wherein the nozzle assembly further comprises a stiffening rib configured to deflect the flexible panel.
 18. The gas turbine engine of claim 17, wherein the nozzle assembly further comprises an actuator connected to the rib and configured to operatively rotate the stiffening rib and deflect the flexible panel in the throat area and an exit area of the nozzle.
 19. The gas turbine engine of claim 17, wherein the nozzle assembly is a third stream exhaust nozzle assembly.
 20. The gas turbine engine of claim 17, wherein the nozzle assembly further comprises a support structure to support the flexible panel and wherein the flexible panel further comprises a stiffening stay configured to maintain a profile of the throat area. 